My brother just picked up his C63 Black series - it hands down blows away any M3 I have ever seen. The car is extremely wide and aggressive, and from any angle it makes the M3 look weak in comparison. The brakes blow away those on the M, it accelerates much faster and handles better as well. The one thing I absolutely despised about the regular C63 was the shit transmission, and the dual clutch MCT in the black series is no different than the DCT in my car - I absolutely love it. The car truley is nothing like a regular C63 whatsoever. Even with my car having 30k invested into it (supercharger, wheels, brakes, suspension etc...) the C63 still effortlessly wins in my book in every aspect except straight line speed (that can easily be fixed with headers/tune....or a simple weistec blower). The biggest difference between the two is the rear of the car, the flared body on the C63 is significantly wider than that of the M, heres a quick pic I took:

Also, the interior of the M is completely outdated in comparison to the Black Series...the suede interior, red stiching, red seatbelts, etc... all make you feel in a more dedicated racecar than a regular M3. You see at least 3-5 M3's on the road a day around here, as where I've never seen a C63 BS in my life. Exclusivity on that car is on a complete other level.

Please enlighten me a bit, should I call you Dr. Mario Theissen?

How did he know it handles better? Did he drive it against the M3 GTS? Is he the well-known Stig, Chris Harris, or someone that I'm not aware of?